1. Field of the Invention
The present invention relates to an air cooling device and an air cooling method for efficiently cooling air at high temperature in summer or the like. More particularly, the present invention relates to an air cooling device for cooling air in office buildings, hospitals, and factories, and an air cooling method using the same.
2. Description of Background Art
Energy used for air conditioning in office buildings, factories, and the like accounts for 30% or more of the energy consumed in Japan. Therefore, reduction of energy consumption used for air conditioning has become a pressing issue. Conventionally, circulating air or intake air in office buildings or factories is supplied to a fin coil-type heat exchanger in which a refrigerant or cooling water is circulated, and cooled when passing through the fin coil. However, in the case of using the fin coil-type heat exchanger, a large amount of cooling water is necessary in comparison with the amount of air to be cooled (liquid-gas ratio is high). Therefore, a large amount of electric power is needed to operate a pump for circulating cooling water and the like. Moreover, the fin coil-type heat exchanger has a large pressure drop. Furthermore, water drops adhering to the fin coil has a considerable effect on thermal conduction, whereby thermal efficiency is significantly decreased. As a method for removing water drops adhering to the fin coil, a method of blowing off the water drops by using a blower or the like has been proposed. However, since space for installing the blower or the like and additional electric power are necessary, it is not desirable to use this method from the viewpoint of space efficiency and power saving.
In order to overcome the above problems, a method of allowing water to come directly into contact with air by using an oblique honeycomb instead of the fin coil has been proposed. For example, Japanese Patent Application Laid-open No. 2000-317248 discloses a method of removing NOx and the like contained in air by serially connecting wetted-wall columns in which water flows along the wall and allowing air to pass through the wetted-wall columns. However, in the case of using this method as an air cooling method, since water warmed when flowing through the wetted-wall column is allowed to flow through the next wetted-wall column, the air cannot be sufficiently cooled. Moreover, since it is necessary to provide pumps for supplying water to each column, installation and operation costs for the pumps are necessary.
As another method of allowing water to come directly into contact with air by using the oblique honeycomb instead of the fin coil, a method of cooling warm or hot water with air by using an oblique honeycomb made of conventional polyvinyl chloride as a cooling tower is known. However, since the oblique honeycomb is made of conventional polyvinyl chloride, warm water or the like is repelled from the surface of the oblique honeycomb and falls in the shape of water drops. Specifically, since the surface of the oblique honeycomb is not uniformly wetted by warm water or the like, the large surface area of the oblique honeycomb cannot be fully utilized. This results in thermal efficiency lower than that of the fin coil-type cooling device. Therefore, the oblique honeycomb cannot be used as an air cooling device having high thermal efficiency.
Accordingly, an object of the present invention is to provide an air cooling device excelling in thermal efficiency, having a small liquid-gas ratio and a small pressure drop, and capable of saving space and energy and reducing cost, and an air cooling method using the same.
In view of the above situation, the present inventor has conducted extensive studies and found that an air cooling device having high thermal efficiency, a small liquid-gas ratio, and a small pressure drop, and saving space and energy can be realized by using at least one cooling unit which includes an oblique honeycomb, a cooling water supply device, and a water receiving section, and limiting the height of one oblique honeycomb in the cooling unit within a specific range. This finding has led to the completion of the present invention.
Specifically, the present invention provides an air cooling device comprising at least one cooling unit which comprises an oblique honeycomb which has front, rear, upper, and lower openings and is disposed so that air to be cooled is introduced into the front opening and cooled air is discharged from the rear opening, a cooling water supply means which supplies cooling water to the upper opening of the oblique honeycomb, and a water receiving section which receives discharge water discharged from the lower opening of the oblique honeycomb, and a blower means which introduces air to be cooled into the front opening of the oblique honeycomb and allows cooled air to be discharged from the rear opening of the oblique honeycomb, wherein the height of one oblique honeycomb in the cooling unit is 200 to 800 mm.
The present invention also provides an air cooling method using the above air cooling device, comprising introducing air to be cooled into the front opening of the oblique honeycomb of the cooling unit, and allowing cooled air to be discharged from the rear opening of the oblique honeycomb.